Moneypenny.com, a service provider to global businesses, has released an index that ranks the 50 U.S. states according to which are forecast to be richest and poorest in five years. Researchers predicted the future values of real GDP, personal income per capita and Zillow home value data based on historical values by using an exponential smoothing algorithm to account for seasonality trends. To create the index, they weighted the three data points with the highest value for each state assigned a figure of one. All the remaining values were then scaled back, normalized and added together to give a total score figure. See the gallery above for the 12 states predicted to be poorest by 2025.